Combined skimmer and sweater



2 Shets-Sheet -'1 lNo ModlL) I W. H: HOWARD.-

COMBINED SKIMMER AND SWEATER; No. 502,122. Paten-ted' July 25,1893,

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2 Sheets-Sheet 2.

{No Model.)

W. H. HOWARD. I 0 COMBINED SKIMMER ,AND SWEATER.-

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UNITED STATEs \VILLIAM H. HOWARD, OF PUEBLO, COLORADO.

COMBINED SKIMMER AND SWEATER.

SPECIFICATION forming part of Letters Patent No. 502,122, dated July 25,1893.

Application filed January 31, 1893. Serial No. 460,297. (No model.)

To (ZZZ whom it may concern:

Be it known that 1, WILLIAM H. HOWARD, of Pueblo, in the county ofPueblo and State of Colorado, have invented a new and Improved OombinedSkimmer and Sweater, of which the following is a full, clear, and exactdescription.

The invention relates to apparatus used for desilverizing lead bullionin the zinc pot.

The object of the invention is to provide a new and improved combinedskimmer and sweater designed for use in zinc pots containing the moltenargentiferous lead and metallic zinc, the device being arranged forconveniently skimming the zinc and silver alloy rising to the surface,and also for sweating out the mechanically combined lead removed fromthe pot with the scum.

The invention consists of hinged perforated plates adapted to be passedinto the zinc pot in a folded condition, and then opened therein andraised to carry off the zinc and silver alloy and to drain off themetallic lead.

The invention also consists of certain parts and details, andcombinations of the same, as will be hereinafter described and thenpointed out in the claims.

Reference is to be had to the accompanying drawings forming a part ofthis specification, in which similar letters of reference indicatecorresponding parts in all the figures.

Figure l is an end elevation of the improvement as applied to the zincpot, the latter being shown in section. Fig. 2 is a sectional sideelevation of the same, and Fig. 3 is a sectional plan view of the sameon the line 3-3 of Fig. 2.

The improved device is used in connection with the ordinary zinc pot A,containing the molten argentiferous lead and the metallic zinc addedtothe same and thoroughly stirred therein, so as to form, when the potcools, a zinc scum which carries the silver-and rises to the surface tobe skimmed off and removed from the pot.

The device is provided with two perforated plates B and 13', preferablymade semi-circular in shape to conform to the contour of the pot A, thesaid plates being connected with each other by hinges 13 at their upperedges and are also pivotally-connected at B at the center with the lowerend of a screw rod O screwing in a suitable nut D held on a carriage Emounted to travel longitudinally on a suitable overhead track F to carrythe device to and from the pot A.

On the screw rod 0 is mounted to slide loosely a sleeve G provided witharms H, the lower ends of which are pivotally-connected by links I withbrackets J projecting from the free ends of the plates B and B, so thatwhen the sleeve G is caused to slide upward on the rod O the plates Band B swing upwardly through the molten mass in the pot A until theplates finally assume a horizontal position near the top of the pot A,as indicated in dotted lines in Fig.1. 7

In order to raise the sleeve G, I connect the horizontal parts of thearms H with chains K,

winding on drums L both secured on a horizontally-extending shaft Lmounted to turn in suitable bearings secured to the carriage E. On theshaft L is secured a worm wheel L in mesh with a worm L secured onashaft L also mounted to turn in suitable bearings on the carriage E andcarrying at one outer end asprocket wheel L over which passes a chain Ladapted to be actuated by the operator for conveniently turning the saidwheel L to rotate the shaft L and the worm L which latterthen rotatesthe worm wheel L and the shaft L so that the drums L wind up the chainsK to raise the sleeve G to open the plates B and B, as before described.When the wheel L is turned in the opposite direction, the drums L, L,are rotated to unwind the chains K, so as to lower the sleeve G on g thescrew rod O to close the plates B and 13 before the latter are'insertedinto the pot A. The nut D previously mentioned carries a bevel gearwheel N in mesh with a bevel pinion N secured on one end of a shaft 0journaled in suitable bearings on the carriage E. On the outer end ofthis shaft 0 is secureda sprocket wheel 0' over which passes a sprocketchain O also adapted to be actuated by the operator in charge of thedevice for turning the said wheel 0', the shaft 0, pinion N and gearwheel N to rotate the nut D, so as to raise and lower the screw rodO tomove the apparatus in and out of the pot A.

The operation is as follows: When the pot A is filled with argentiferouslead and on its ICO surface floats the zinc and silver alloy ready toskim oil", then the two semi-circular plates B and B are lowered intothe pot A in a closed position, and then the operator manipulates thechain L so as to wind up the chains K on the drums L, to lift the sleeveG, as previously described, whereby the plates B and B, are opened tofinally assume a horizontal position near the top of the pot A, and thezinc scum floats on the top of the plates B and B on the surface of thelead. The device is then very slowly raised by the operator manipulatingthe chain O so as to revolve the nut D to raise the screw rod 0 and theplates B and B held thereon and extended in a horizontal position, aspreviously described. During this operation of slowly raising theperforated plates B and B, any scum near the edges of the pot is movedby a suitable tool upon the top of the plates. As soon as the latter areraised until the upper surface on which the zinc scum rests is out ofthe lead, then the apparatus is allowed to remain still for a fewminutes to permit the mechanically combined lead in the zinc scum todrain outand back into the potAover the edges and through theperforations of the plates B and B. \Vhen this so-called sweating hasgone far enough, the plates B and B are rapidly raised by further raisingthe screw rod 0, as previously described, until the plates are entirelyfree of the pot and then the carriage E with the apparatus supportedthereon is pulled along outside of the pot and the skimmings on theplates B and B are dumped on the floor by again closing the plates B andB in the manner previously described.

It will be seen that this apparatus acts both as a large skimmer capableof removing the whole of the scum in one operation, and also utilizesthe heat of the molten lead in the pot A to perform the process ofsweating to remove the surplus lead.

Having thus fullydescribed my invention,I claim as new and desire tosecure by Letters Patent- 1. The method of skimming molten lead whichconsists in passing a perforated skimmer beneath the scum and raisingthe skimmer slowly until its upper surface on which the scum rests isout of the lead, then holding the skimmer stationary on the surface ofthe lead (where it will be kept hot.) until the mechanically combinedlead in the scum is freed therefrom and drains through the skimmer,substantially as shown and described.

2. A lead skimming apparatus comprising a carriage, a skimmer suspendedbelow the carriage and adapted to be raised and lowered bodily towardand from the carriage; said skimmer being pivoted at one edge to itssuspending medium to permit it to be swung down to enter the pot withits lower tr free edge and adjusting mechanism for swinging the skimmeron its axis, substantially as set forth.

3. A combined skimmer and sweater, comprising perforated plates hingedtogether, a screw rod adapted to be raised and lowered andpivotally-connected with the said plates, and means, substantially asdescribed, for opening and closing the said plates, as set forth.

4. A combined skimmer and sweater, comprising perforated plates hingedtogether, a screw rod adapted to be raised and lowered andpivotally-connected with the said plates, means, substantially asdescribed, for opening and closing the said plates, and a carriage forsupporting the said plates, screw rod and means for actuating the same,substantially as shown and described.

5. A combined skimmer and sweater, comprising a screw rod adapted to beraised and lowered, perforated plates hinged on the said screw rod, asleeve fitted to slide on the said screw rod, and links pivotally-connecting the said sleeve with the free ends of the saidplates, substantially as shown and described.

6. A combined skimmer and sweater, comprising a screw rod adapted to beraised and lowered, perforated plates hinged on the said screw rod, asleeve fitted to slide on the said screw rod, links pivotally-connectingthe said sleeve with the free end of the said plates, and means,substantially as described, for raising and lowering the said sleeve toopen and close the plates, as set forth.

7. A combined skimmer and sweater, comprising a screw rod adapted to beraised and lowered, perforated plates hinged on the said screw rod, asleeve fitted to slide on the said screw rod, links pivotally-connectingthe said sleeve with the free end of the said plates, means,substantially as described, for raising and lowering the said sleeve toopen and close the plate and means, substantially as described, forraising and lowering the said screw rod, as set forth.

WILLIAM H. IIOl/VAR D.

